Methods for assessing integral parameters of arterial stiffness: comparative analysis and new potential

Aim. To develop a new method for calculating integral parameter of arterial stiffness — volume elastic modulus (Ev).

Material and methods. A retrospective analysis of integral hemodynamic parameters of 1660 patients (women, 60%, 58,6±16 (M±σ) years of age; men, 40%; 53,5±17,7 (M±σ) years of age) was carried out. The first group consisted of 898 patients with normal blood pressure (BP) (<140/90 mm Hg). The second group included 762 patients with hypertension (HTN). We studied following parameters: systolic and diastolic BP, stroke volume (SV), heart rate (HR). Calculation of Ev, total peripheral resistance (TPR), mean arterial pressure (MAP), systemic arterial compliance (SAC) and total bulk modulus (Е_∑) was carried out.

Results. The analysis showed that BP, SV, TPR and all parameters of the integral stif-f ness (E_v, SAC, and E_∑) were significantly higher in hypertensive patients. Ev had a strong positive correlation with SAC (r=0,996, p<0,0011 and E_∑ (r=0,985, p<0,001). This made it possible to calculate the dependence of Ev on SAC and E_∑ using regression analysis.

Conclusion. Using linear regression, the formula for calculating the E_v using SAC was obtained, which has a high accuracy at a heart rate of 60 to 90 bpm (error, no more than ±5%). With tachycardia and bradycardia, the error exceeds ±5%. In these cases, it is necessary to calculate the Ev using the mathematical model of A. E. Teregulov.

Calculation of Ev from Ez using the diastolic duration calculated by the Karpman formula does not give a sufficiently reliable result. Thus, a direct measurement of diastolic duration using echocardiography is required.

1. Niiranen TJ, Kalesan B, Hamburg NM, et al. Relative contributions of arterial stiffness and hypertension to cardiovascular disease: The Framingham Heart Study. J Am Heart Assoc. 2016;5(11):e004271. doi:10.1161/JAHA.116.004271.

2. Nikitin YuP, Lapitskaya IV. Arterial stiffness: indicators, determination methods and methodological difficulties. Kardiologiya. 2005;45(11):113-20. (In Russ.)

3. Spronck B, Humphrey JD. Arterial stiffness: different metrics, different meanings. Journal of Biomechanical Engineering. 2019;141(9):091004. doi:10.1115/1.4043486.

4. Teregulov YuE. To a technique of definition of types of central hemodynamic in clinical practice. Prakticheskaya meditsina. 2011;4(52):138-40. (In Russ.)

5. Van Bortel LM, Dupres D, Starmam-Kool MJ, et al. Clinical application of arterial stiffness, Task Forse III: recommendations for user procedures. Am J Hypertens. 2002;15:445-52. doi:10.1016/s0895-7061(01)02326-3.

6. Savitskiy NN. Biophysical fundamentals of blood circulation and clinical methods for the study of hemodynamics. Moscow: Medicine, 1974. p. 307. (In Russ.)

7. Teregulov YuE, Teregulov AE. The rigidity of the arterial system as a risk factor for cardiovascular events: methods of assessment. Prakticheskaya meditsina. 2011;4(52):133-7. (In Russ.)

8. Teregulov YuE, Mayanskaya SD, Teregulova ET. Determination of differentiated hemodynamics types based on the assessment of integral circulation indicators in healthy people and patients with hypertension. Kazanskii Medicinskii Jurnal. 2015;96(6):911-7. (In Russ.) doi:10.17750/KMJ2015-911.

9. Kubyshkin VF. Cardiodynamic phase syndromes. Kiev: Health, 1983. p. 192. (In Russ.)